Traditionally, automotive heater units constructed from aluminum have been costly for low volume build because of the expense of dies or plastic molds to fabricate the tanks in such heater units. For each tank length for a specific application, separate dies or molds must be purchased. The use of extruded aluminum tanks reduces such tooling costs since only one inexpensive extrusion die is required to manufacture different length tanks for different capacity heater units.
Present heater cores include the tube passes and air centers wherein the air centers are connected to headers. The tanks are then placed against the headers at flat sealing perimeter surfaces therebetween. The assembly is brazed for forming a structurally cohesive core in which the headers are sealed to the tanks; the tubes are sealed to the header and the cooling fins or air centers are bonded to the tubes.
Thereafter, the heater core is assembled within the vehicle heating system in an air flow pass therethrough. In the past, a plastic case is provided to secure the heater core in the passage. Presently, the sides of the heater core are connected in the plastic case by a steel strap connected thereto and wrapped about each tank, and a polyurethane seal is located between the header and case to eliminate leakage. The plastic case is fastened to the module to secure the heater core into the vehicle heater case and air flow path.
The problem with this type of assembly is that the tanks are bulky and must be of greater width to receive the headers in the present form thereby undesirably increasing weight and size requirements. Furthermore, steel straps for securing the heater to the plastic case are difficult to assemble.